Aluminum alloys are commonly used in the manufacture of housings of mobile electronic devices such as mobile phones, due to its good thermal conductivity and mechanical strength. Although this aluminum alloy housing can obtain a better appearance by subjecting to an anodic surface treatment, it usually cannot be manufactured by die-casting, but must be manufactured by extruding or numerical control processing from forged blanks, which results in a significant increase in costs and a significant reduction in efficiency. On the other hand, as for aluminum alloy housings with good die-casting properties, although they can form a frame structure by die casting, they usually cannot be subjected to the anodic surface treatment to obtain a better appearance due to the existence of chromatic aberration and other reasons.